- In 1810 Mexico won the War for Independence from Spain. Led by Father Miguel Hidalgo y Costilla, it ratified a progressive Constitution in 1824 that established a federal government with considerable powers given to the states.
- During the Texas Revolution, the Mexican President Santa Anna was captured and forced to sign the Treaty of Velasco.
In 1718, San Antonia was the first settlement to be established in Texas by Spanish missionaries. The area remained sparsely populated due to its vastness and hostility from Native Indian tribes. In 1810, Mexico won the War for Independence from Spain. Led by Father Miguel Hidalgo y Costilla, it ratified a progressive Constitution in 1824 that established a federal government with considerable powers given to the states. The Mexican government allowed American settlers to claim land in the Texas region as colonists, after taking an oath of allegiance and converting to Catholicism. Thousands of Americans accepted the invitation, resulting in a population explosion and, over time, the number of Mexican of Spanish descent was higher than that of Americans.
The new settlers were not satisfied with the way the Mexican government was managing the territory, however, and so there was a struggle for independence with a unity of purpose for both the Americans and Mexicans living in the area.
In 1835 there was a revolution that led to the Independence of Texas from Mexico with Sam Houston as President. The Mexican President Santa Anna was captured and forced to sign the Treaty of Velasco. The Republic of Texas was unable to permanently defend itself against Mexican troops and decided to negotiate with the US to join the Union in 1845.
The Manifest Destiny, the belief that America was specially ordained by God to spread the influence of its democracy and institutions to uncivilised people on the continent, was the main force behind the Mexican American war. President Polk offered to buy the southwest land from Mexico, but Mexico declined, causing tensions that contributed to the war.
Mexico was not happy with Texas joining the Union and also disagreed with the US on the border. Mexico placed the border at the Nueces River while Texas claimed the border was further south at the Rio Grande River.
President Polk sent troops to protect the Texas border where they met the Mexican forces and a shouting brawl ensued. On 7 July 1846, the US declared war on Mexico. The Mexican army was led by Santa Anna and the US forces by General Zachary Taylor. They fought at the Palo Alto where the Mexicans were forced to retreat.
General Taylor advanced into Mexico fighting at the city of Monterrey and a mountain pass called Buena Vista. In the battle at Buena Vista Taylor’s 5,000 troops defeated Santa Anna’s 14,000 men.
President Polk did not trust General Taylor and instead of replenishing his troops to capture Mexico City, he sent General Winfield Scott who captured it in August 1847.
The Mexicans were forced to concede defeat and agree to a treaty called the Treaty of Guadalupe Hidalgo. In the settlement, Mexico agreed to border Texas at the Rio Grande and sold 55% of its land to the US at 15 million dollars. Presently this land makes up the states of California, Nevada, Utah, Arizona and parts of Wyoming, Oklahoma, New Mexico, and Colorado.
During the US invasion in Mexico, the US army attacked a Military Academy at Chapultepec Castle in Mexico City. Six Mexican students died defending the castle. They are remembered as the Ninos Heroes (boy heroes) in Mexico with a national holiday on 13 September.